Factors in Selecting an Air Knife – Size, Materials, Stock Levels, Accessories

Super Air Knife Family

EXAIR has been manufacturing Intelligent Compressed Air® products since 1983.  In the beginning, the Standard Air Knives and Full Flow Air Knives were very effective at that time.  But as leaders in this market, EXAIR did not want to stop there.  We were able to engineer a more efficient, more powerful, and much safer air knife, the Super Air Knife.  In this blog, I will discuss the features and benefits that the Super Air Knives can offer.

Bernoulli’s principle explains how a high velocity fluid can generate a low pressure.  The EXAIR Super Air Knife creates a high velocity air stream to produce a low pressure to entrain ambient air.   What does this mean for you?  It will save you much money by using less compressed air.  The mass of the ambient air is added into the air stream to give a strong blowing force.  The Super Air Knife has an amplification ratio of 40:1. For every 1 part of compressed air, 40 parts of ambient air is drawn into the blowing air stream.  Ambient air is free, and compressed air is expensive.  EXAIR was able to engineer a design to use the Bernoulli’s principle to make one of the most efficient air knives in the market place.

EXAIR Super Air Knife model 1100108

What else makes EXAIR unchallenged?  We manufacture and stock the widest range in lengths and materials.  To start, EXAIR has Super Air Knives ranging from 3” to 108” (76mm to 2,743mm) in three different materials; aluminum, 303 stainless steel, and 316/316L stainless steel.  There is no-one else in this industry that can manufacture to those lengths.  EXAIR also offers Super Air Knives in PVDF material with Hastelloy hardware for chemical resistant applications from 3” to 54” (76mm to 1,372mm).  Depending on the temperature requirement, chemical resistance, OSHA and FDA regulations, or application details, we probably will have one on the shelf for you.  If EXAIR does not have it, we can make special air knives in different lengths and materials to best fit your application.

Some interesting features for the Super Air Knives are as follows.  They have a compact design that can fit into tight places for blowing and cooling.  The footprint is very small compared to blower-air knife system.  They do not have any moving parts to wear or maintenance to do.  They only need clean compressed air to work.  They blow a laminar air stream which reduces noise levels and create a consistent force along the entire length.  An even force will give you tighter control for blowing applications which will cut compressed air usage unlike the inconsistent and turbulent air flows caused by drilled pipes.

To adjust the force and air usage, this can be easily controlled with a regulator.  The advantage that EXAIR Super Air Knives have is the replaceable shims.  So, you can increase or decrease the gap to get a variety of force ratings.  The Aluminum version uses colored plastic shims for visual verification.  They come stock with a 0.002” (0.05mm) red shim installed.  We have other thicknesses in our Shim Sets which includes a 0.001” (0.03mm), 0.003” (0.08mm), and a 0.004” (0.10mm) colored as amber, green, and tan respectively.  The Stainless Steel Super Air Knives come with a stainless steel shim for higher temperatures and chemical resistance.  Stock units have the 0.002” (0.05mm) thickness as well.  The Shim Sets come with three additional 0.002” (0.05mm) shims to stack.  Similarly, the PVDF Super Air Knives use a PTFE shim for maximum chemical resistance.  It is also 0.002” (0.05mm) thick, and there are three more shims in the Shim Set.  This unique feature of using shims allows for the most flexibility in creating forces for different applications ranging from a blast to remove rocks from a conveyor to a breeze for light duty work.

Super Air Knife Kit

We also offer the Super Air Knives in kits as a more complete system.  The kit includes a filter, regulator and the above-mentioned Shim Set.  The filter removes the debris and water from the compressed air line to optimize the performance of the air knife as well as keeping your product clean.  The regulator is used to make the “fine” adjustment to the blowing force while the shim set is used as the “coarse” adjustment.  EXAIR sells this kit as one model number for simple ordering, and the accessories are properly sized to not hinder the performance of the Super Air Knife.

To optimize the system even more, EXAIR offers a Deluxe Kit for the Aluminum and Stainless Steel models.  This includes the accessories in the kit above, plus an Electronic Flow Control, or EFC.  This exclusive instrument uses a photoelectric eye to start a timing sequence to control a solenoid valve.  So, when a part is not in front of the Super Air Knife for cleaning or cooling, the compressed air is turned off.  This will save you even more money and maximize your efficiency to only blow air when needed.

Plumbing Kits

For the longer Super Air Knives, EXAIR can install a Plumbing Kit, or PKI, to help attach your compressed air to the Air Knife.  They are designed to help lessen the time for install as well as to properly supply compressed air equally along the entire length, specifically for 24” (610mm) and longer.  We can offer the Plumbing Kit separately if you find that it could benefit your fabricators during installation.  EXAIR also offers a Coupling Kit for the Aluminum and Stainless Steel versions.  If you need to extend past the 108” (2,743 mm) width, the Coupling Kit is designed to mount Super Air Knives together at the ends.  You will still get that consistent blowing force along the multiple of Air Knives.  Another helpful accessory is the Universal Air Knife Mounting System.  It has a bracket and an articulated arm that can reach up to 30” (762mm).  With this system, you can position your air knife securely and precisely in any orientation.  It attaches easily to your Super Air Knife and gives you the flexibility to maximize the blowing effect at your target.

Universal Mounting System

With the today’s cost in making compressed air, it is important to use it as efficiently as possible.  The Standard and Full Flow Air Knives would be good options to use.  But the best way to conserve is with the Super Air Knife.  If you have any questions about the Super Air Knife or if you would like to discuss an application, you can contact an Application Engineer at EXAIR.   We will be glad to help you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb